#define BRW_MASK_ENABLE 0
#define BRW_MASK_DISABLE 1
-/* Sandybridge is WECtrl (Write enable control) */
+/** @{
+ *
+ * Gen6 has replaced "mask enable/disable" with WECtrl, which is
+ * effectively the same but much simpler to think about. Now, there
+ * are two contributors ANDed together to whether channels are
+ * executed: The predication on the instruction, and the channel write
+ * enable.
+ */
+/**
+ * This is the default value. It means that a channel's write enable is set
+ * if the per-channel IP is pointing at this instruction.
+ */
#define BRW_WE_NORMAL 0
-#define BRW_WE_KILL_PRED 1
+/**
+ * This is used like BRW_MASK_DISABLE, and causes all channels to have
+ * their write enable set. Note that predication still contributes to
+ * whether the channel actually gets written.
+ */
+#define BRW_WE_ALL 1
+/** @} */
#define BRW_OPCODE_MOV 1
#define BRW_OPCODE_SEL 2